Definition and Epidemiology

Cholelithiasis and cholecystitis are worldwide disorders that result from inflammatory, infectious, neoplastic, metabolic, and congenital conditions. Gallbladder disease affects all cultures and is prevalent in most Western countries.¹ The highest incidence of acute cholecystitis occurs in adults of middle age and older. Although gallbladder disease also occurs in adolescents, it is seen at increased rates after the age of 40 years. Acalculous cholecystitis is less common but is associated with more severe morbidity. Risk factors for gallbladder disease include ethnicity, with Native Americans having an increased incidence in North America. Moreover, gallbladder disease is more common in females and during pregnancy. Other risk factors include family history, diet, medications (e.g., estrogen, oral contraceptives, thiazide diuretics), obesity, rapid weight loss, history of gastric bypass surgery, and hyperalimentation, as well as comorbid disorders such as diabetes, Crohn disease, alcoholic and biliary cirrhosis, and hyperparathyroidism (Box 129-1).

Physician consultation is indicated for acute cholecystitis.

Pathophysiology

Gallstones are formed from bile constituent crystals and are divided into three primary types of stones: cholesterol, pigmented, and mixed. Small gallstones pass uneventfully through the common bile duct and do not cause distress. Larger stones may obstruct the cystic or common bile duct, causing increased pressure to the ductal system that results in pain, nausea, and vomiting as a result of the contractile spasms of the smooth muscle. Because of the blockage, bile is prevented from entering the duodenum, reducing the body’s ability to digest fat. The undigested fat passes from the small intestine into the large intestine, where bacteria convert the excess undigested fat into fatty acid derivatives. The fatty acid derivatives alter water absorption from the colon, which results in diarrhea and excess fluid loss. The obstruction prevents bile secretion into the small intestine, causing jaundice.

The gallbladder becomes inflamed as a result of various processes, including continued blockage of the cystic or common bile duct. This inflammation causes the release of prostaglandins and other chemicals that further inflame gallbladder tissue. In the majority of cases, bacterial infections contribute to the inflammatory response in acute cholecystitis.² Human immunodeficiency virus (HIV) disease may lead to opportunistic infections of the biliary tract. The most common bacteria involved in biliary tract infections are Escherichia coli, Klebsiella organisms, Enterobacter, and enterococci.³ Gangrene of the gallbladder and possible perforation can result if the process is not stopped.

Cholecystitis can also occur in the absence of stones; this condition is labeled acute or chronic acalculous cholecystitis. Acalculous cholecystitis is classified as acute if the duration of symptoms is less than 1 month and as chronic if the symptoms have been present longer than 3 months. The pathophysiology of this condition is poorly understood. The inflammatory process is similar to that of cholecystitis except that gallstones are not present. A common cause of chronic acalculous cholecystitis is biliary dyskinesia. Risk factors associated with acute acalculous cholecystitis are outlined in Box 129-2.

Most patients with gallstones are asymptomatic.⁴ Classically, symptomatic cholelithiasis manifests as biliary colic with intermittent or steady, right upper quadrant abdominal pain that radiates to the right posterior shoulder within an hour of eating any type of large meal, specifically a meal with a high fat content. The pain may be constant or intermittent and tapering, sometimes without complete relief. It is described as mild to severe and lasts 1 to 6 hours. The biliary colic is accompanied by nausea and vomiting. There can be a history of these episodes, which increase in frequency.

Acute cholecystitis develops in a manner similar to symptomatic cholelithiasis, but biliary colic lasts longer than 4 to 6 hours. There usually is a history of intermittent colic consistent with chronic cholecystitis, and the patient may have anorexia, fever, and chills with the nausea and vomiting observed in symptomatic cholelithiasis. As the gallbladder becomes progressively inflamed, the pain in the right upper quadrant becomes sharp. The Charcot triad of right upper quadrant abdominal pain, fever, and jaundice can be observed if a stone is lodged in the common bile duct.

Patients with chronic cholecystitis often describe a recurrent, mild to moderate, right upper quadrant and epigastric abdominal pain accompanied by nausea and vomiting. The pain may radiate to the region of the posterior right shoulder and scapula and is often associated with the eating of fatty foods.

Traditionally, patients with acute acalculous cholecystitis are critically ill and require hospitalization. Presentation includes generalized complaints, fever, nausea, vomiting, and loss of appetite. The patient often has no significant medical history, although surgery, trauma, burns, and other disorders have been associated with acalculous cholecystitis. This condition should be considered in all patients who are seen with right upper quadrant pain in the absence of gallstones.

Physical Examination

Depending on the severity of the condition, the physical examination in symptomatic cholelithiasis and chronic cholecystitis may be unremarkable. Right upper quadrant abdominal pain may be accompanied by tenderness. The diagnosis is based on the history, the exclusion of other disorders, and the results of the gallbladder ultrasound examination.

With acute cholecystitis, patients may have moderate distress from systemic toxicity, including tachycardia and fever. The right upper quadrant abdominal pain is associated with tenderness and muscle guarding or rigidity. The gallbladder is not commonly palpable, but a distended tender gallbladder confirms the diagnosis. Hypoactive bowel sounds and presence of Murphy sign (an inability to take a deep breath because of the discomfort during palpation beneath the right costal margin) may be noted. Dehydration is not uncommon. Jaundice is present in some patients and is the result of biliary obstruction or chronic hemolysis.

The physical findings in acalculous cholecystitis are similar to those of symptomatic gallstones: right upper quadrant pain, vomiting, fever, jaundice, and presence of Murphy sign.